Demonstration of 651†nm InGaN-based red light-emitting diode with an external quantum efficiency over 6% by InGaN/AlN strain release interlayer.

This work reports a high-performance InGaN-based red-emitting LED with a strain-release interlayer (SRI) consisting of an InGaN stress-release layer (SRL) and an AlN dislocation confinement layer (DCL) in unintentionally doped GaN (u-GaN). The SRL introduces a tensile strain which could decrease the in-plane compressive stress of the u-GaN layer, while the DCL could reduce the dislocation density and thus improve the crystal quality of the u-GaN layer. Consequently, a high-efficiency InGaN-based red-emitting LED with a peak wavelength of 651 nm and an external quantum efficiency of 6.04% is realized. In addition, the room-temperature photoluminescence (PL) mapping emission wavelength is uniform across a 4-inch wafer with a standard deviation of 3.3 nm. Therefore, the proposed SRI offers good potential for mass-producing high-performance and long-wavelength InGaN-based red-emitting LEDs.

Phonon-assisted upconversion charging in Zn3Ga2GeO8:Cr(3+) near-infrared persistent phosphor.

We report a new phonon-assisted upconversion excitation design that enables the excitation energy to be lower than the persistent luminescence emission energy in persistent phosphors. We demonstrate this upconversion excitation concept in Zn3Ga2GeO8:Cr(3+) near-infrared persistent phosphor by achieving Cr(3+) 700 nm persistent emission using 800 or 980 nm laser diode excitation. Depending on the sample temperature, the excitation photon energy can be tuned, and the persistent luminescence intensity can be adjusted. Depending on the excitation power, the upconversion trap filling process involves either one photon (for filling low-energy traps) or two photons (for filling high-energy traps). Our research provides a major step toward manipulating the electronic excitation in persistent luminescence, which has implication for many applications.

Nanoscintillator-mediated X-ray inducible photodynamic therapy for in vivo cancer treatment.

Photodynamic therapy is a promising treatment method, but its applications are limited by the shallow penetration of visible light. Here, we report a novel X-ray inducible photodynamic therapy (X-PDT) approach that allows PDT to be regulated by X-rays. Upon X-ray irradiation, the integrated nanosystem, comprised of a core of a nanoscintillator and a mesoporous silica coating loaded with photosensitizers, converts X-ray photons to visible photons to activate the photosensitizers and cause efficient tumor shrinkage.

Detection of up-converted persistent luminescence in the near infrared emitted by the Zn3Ga2GeO8:Cr³âº, Yb³âº, Er³âº phosphor.

Up-conversion luminescence and long-persistent luminescence are two well-studied, special luminescence processes. By combining the unique features of these two luminescence processes, here we design a new luminescence process called up-converted persistent luminescence (UCPL), which enables us to generate persistent luminescence having an emission energy higher than the excitation energy. Guided by the UCPL concept, we create the first UCPL phosphor Zn3Ga2GeO8:1%Cr3+, 5%Yb3+, 0.5%Er3+ by incorporating an up-converting ion pair Yb3+/Er3+ into a Zn3Ga2GeO8:1%Cr3+ near-infrared persistent phosphor. After being excited by a 980 nm laser, the phosphor emits long-lasting (>24 h) near-infrared persistent emission peaking at 700 nm. The UCPL concept and the associated phosphors are expected to have important implications for several fields such as biomedical imaging.

Effect of primary particle size on colloidal stability of multiwall carbon nanotubes.

Multiwall carbon nanotubes (MWCNTs) are one type of nanoparticles that have various special properties and potential applications. Due to their increasing production and potential toxicological effects, the environmental behavior and transport of MWCNTs have become important research topics. Particle size is one of the important properties of nanoparticles, yet its effects on MWCNT environmental behaviors have not been fully investigated. In this study, we tested how the length of MWCNTs influenced their settling in the presence of Na(+) and/or natural organic matter (NOM), and postulated the governing mechanisms. The results showed that when adding Na(+) the shorter MWCNTs exhibited preferential aggregation and settling. One possible reason could be that shorter MWCNTs possess larger specific surface area and consequently stronger attraction forces. However, NOM strongly mitigated such aggregation, and helps to disperse MWCNTs regardless of their length and aqueous conditions.

Sunlight-activated long-persistent luminescence in the near-infrared from Cr(3+)-doped zinc gallogermanates.

Visible-light persistent phosphors are being widely used as self-sustained night-vision materials because of their sufficiently strong and long afterglow (>10 h) and their ability to be excited by sunlight as well as room light. In contrast, persistent phosphors for near-infrared (NIR) wavelengths are lacking. Here we report a series of Cr(3+)-doped zinc gallogermanate NIR persistent phosphors that exhibit strong emission at 650-1,000 nm, extending beyond the typical 690-750 nm, and with a super-long afterglow of more than 360 h. These new NIR persistent phosphors are all-weather materials that can be rapidly, effectively and repeatedly charged by natural sunlight in almost all kinds of outdoor environment. Seconds to minutes of sunlight activation can result in more than two weeks of persistent NIR light emission. This new series of NIR persistent materials have potential applications in night-vision surveillance, solar energy utilization and in vivo bio-imaging.

Searching for High-Quality Halide Perovskite Single Crystals toward X-ray Detection.

Metal halide perovskite materials, which combine outstanding physical properties, large absorption coefficient, tailored composition, and low-cost solution-processing, have aroused wide attention for use in various optoelectronic devices. Recently, perovskite single crystals have been rapidly outpacing traditional semiconductor materials in the field of radiation detection. As a prerequisite, achieving high-quality single crystals under controllable solution-phase growth must be tackled to fulfill their full potential as a new paradigm in this stagnated field. This Perspective summarizes the advances in X-ray detectors based on lead halide perovskite single crystals, presenting a comprehensive picture of the relationship among composition engineering, synthesis, and device properties. Additionally, we share our thoughts on several outstanding challenges of perovskite single crystals as promising X-ray detectors and propose possible approaches to the unresolved issues. We anticipate that this Perspective can open up new opportunities to improve their optoelectronic properties, which confers fascinating photonics applications with above and beyond state-of-the-art performance.

Fibrinogen clot induced by gold-nanoparticle in vitro.

The biomedical applications of gold nanoparticle (GNP) are extraordinarily promising due to its special optical properties. However, before transforming into real clinical test, a systematic understanding of the physiological interactions of GNP becomes imperative. For example, protein-GNP interactions and their biological consequences are the most fundamental and exigent for the related studies in cell level. In this study, we report on our findings that the interaction of GNP and fibrinogen (fg) could induce blood clot, one important blood protein, under near-physiological conditions. Firstly, through different characterization methods, namely, UV spectrum, dynamic lighter scattering (DLS) and atomic force microscopy (AFM), fg-GNP clots with the microm size were found to be formed and their average size is time- and concentration dependent. Besides, the dissociation constant was calculated to be 1.36 - 2.05 microg/mL (nM level), suggesting that the interaction between fg and GNP is very strong. Finally, by scrutinizing the fg sequences, this strong binding was found to originate from many Cys residues distributed in alpha, beta, and gamma chains of fg through Au-S bond. Most of these Cys residues are in the form of disulfide bonds, which locate at the central E domain and flank parts of C-terminal and N-terminal in the coil-coil region.

Gd3+-activated narrowband ultraviolet-B persistent luminescence through persistent energy transfer.

This work reports the realization of Gd3+ persistent luminescence in the narrowband ultraviolet-B (NB-UVB; 310-313 nm) through persistent energy transfer from a sensitizer of Pr3+, Pb2+ or Bi3+. We propose a general design concept to develop Gd3+-activated NB-UVB persistent phosphors from Pr3+-, Pb2+- or Bi3+-activated ultraviolet-C (200-280 nm) or ultraviolet-B (280-315 nm) persistent phosphors, leading to the discovery of ten Gd3+ NB-UVB persistent phosphors such as Sr3Gd2Si6O18:Pr3+, Sr3Gd2Si6O18:Pb2+ and Y2GdAl2Ga3O12:Bi3+ as well as five ultraviolet-B persistent phosphors such as Y3Al2Ga3O12:Pr3+, Sr3Y2Si6O18:Pb2+ and Y3Al2Ga3O12:Bi3+. The persistent energy transfer from the sensitizers to Gd3+ is very efficient and the Gd3+ NB-UVB afterglow can last for more than 10 hours. This study expands the persistent luminescence research to the NB-UVB as well as the broader ultraviolet-B spectral regions. The NB-UVB persistent phosphors may act as self-sustained glowing NB-UVB radiation sources for dermatological therapy.

Ultraviolet-C persistent luminescence from the Lu2SiO5:Pr3+ persistent phosphor for solar-blind optical tagging.

Visible and infrared persistent phosphors have gained considerable attention in recent years and are being widely used as glow-in-the-dark materials in dark environments. In contrast, the progress in persistent phosphors emitting at the other end of the spectrum, i.e., the shorter-wavelength ultraviolet-C (UVC; 200-280 nm), is rather slow. Here we report the design and synthesis of a well-performing Pr3+-doped UVC emissive persistent phosphor, Lu2SiO5:Pr3+, which exhibits intense UVC persistent luminescence peaking at 270 nm and a long persistence time of more than 12 h after excitation with a 254 nm UV lamp. Besides, the UVC persistent luminescence of a UV pre-irradiated sample can be repeatedly revived after repeated short-illumination with low-energy white light via a process called photostimulated persistent luminescence. Owing to the distinct spectral features of UVC light and the self-sustained luminescence properties, the UVC persistent luminescence of the Lu2SiO5:Pr3+ persistent phosphor can be clearly monitored and imaged using a corona camera in bright environments including direct sunlight and indoor light. The Lu2SiO5:Pr3+ persistent phosphor is expected to find promising applications in the covert optical tagging field.

Near infrared long-persistent phosphorescence in La3Ga5GeO14:Cr3+ phosphor.

Near infrared (NIR; 660-1300 nm) long-persistent phosphorescence from Cr(3+) ions with persistence time of more than 1 hour was realized in La(3)Ga(5)GeO(14):Cr(3+) phosphor (with or without co-dopants such as Li(+), Zn(2+), Ca(2+), Mg(2+) and Dy(3+)). The NIR phosphorescence can be effectively achieved under UV illumination (~240-360 nm) but is barely achieved by blue light (~480 nm) irradiation, even though the blue light excitation are effective to the NIR fluorescence. The NIR phosphorescence mechanisms were discussed by measuring the irradiation energy dependence of the phosphorescence intensity.

Solar-blind ultraviolet-C persistent luminescence phosphors.

Visible-light and infrared-light persistent phosphors are extensively studied and are being used as self-sustained glowing tags in darkness. In contrast, persistent phosphors for higher-energy, solar-blind ultraviolet-C wavelengths (200-280 nm) are lacking. Also, persistent tags working in bright environments are not available. Here we report five types of Pr3+-doped silicates (melilite, cyclosilicate, silicate garnet, oxyorthosilicate, and orthosilicate) ultraviolet-C persistent phosphors that can act as self-sustained glowing tags in bright environments. These ultraviolet-C persistent phosphors can be effectively charged by a standard 254 nm lamp and emit intense, long-lasting afterglow at 265-270 nm, which can be clearly monitored and imaged by a corona camera in daylight and room light. Besides thermal-stimulation, in bright environments, photo-stimulation also contributes to the afterglow emission and its contribution can be dominant when ambient light is strong. This study expands persistent luminescence research to the ultraviolet-C wavelengths and brings persistent luminescence applications to light.

Correction: Cu2O template synthesis of high-performance PtCu alloy yolk-shell cube catalysts for direct methanol fuel cells.

Correction for 'Cu2O template synthesis of high-performance PtCu alloy yolk-shell cube catalysts for direct methanol fuel cells' by Sheng-Hua Ye et al., Chem. Commun., 2014, 50, 12337-12340, DOI: 10.1039/C4CC04108A.

Efficacy assessment of acupuncture in improving symptoms of uterine fibroids: A randomized controlled trial.

INTRODUCTION: Uterine fibroids are a common benign genital tumor disease in gynecological diseases. It is mainly a change in physical function caused by the growth of smooth muscle cells in the factor uterus. Modern medicine's treatment of this disease is based on the dependence of uterine fibroids on sex hormones. Treatment with antiprogestin and estrogen drugs can reduce the volume of fibroids or slow the rate of increase in volume, thereby achieving the goal of alleviating clinical symptoms. In order to meet the needs of the majority of women of childbearing age and to maintain fertility, acupuncture treatment of uterine fibroids has a broad prospect for development. METHODS/DESIGN: This study plans to select 60 cases that meet the corresponding selection criteria. According to the random principle, they will be divided into intervention group and control group, with 30 cases in each group. The general information, fibroid size, and TCM syndrome scores of the two groups of patients will be compared before treatment. In terms of treatment, the intervention group will be given acupuncture combined therapy; the control group will be given Chinese patent medicine. The treatment cycles in both groups will be three menstrual cycles. After the treatment is completed, the data of the relevant curative effect indicators are analyzed by using SPSS software to draw conclusions. DISCUSSION: We aim to provide higher evidence-based medical evidence for acupuncture treatment of uterine fibroids. TRIAL REGISTRATION: ClinicalTrials.gov, ChiCTR2000030438, Registered on March 01, 2020.

A convenient method for synthesis of glyconanoparticles for colorimetric measuring carbohydrate-protein interactions.

Carbohydrate functionalized nanoparticles, i.e., the glyconanoparticles, have wide application ranging from studies of carbohydrate-protein interactions, in vivo cell imaging, biolabeling, etc. Currently reported methods for preparation of glyconanoparticles require multi-step modifications of carbohydrates moieties to conjugate to nanoparticle surface. However, the required synthetic manipulations are difficult and time consuming. We report herewith a simple and versatile method for preparing glyconanoparticles. This method is based on the utilization of clean and convenient microwave irradiation energy for one-step, site-specific conjugation of unmodified carbohydrates onto hydrazide-functionalized Au nanoparticles. A colorimetric assay that utilizes the ensemble of gold glyconanoparticles and Concanavalin A (ConA) was also presented. This feasible assay system was developed to analyze multivalent interactions and to determine the dissociation constant (K(d)) for five kind of Au glyconanoparticles with lectin. Surface plasmon changes of the Au glyconanoparticles as a function of lectin-carbohydrate interactions were measured and the dissociation constants were determined based on non-linear curve fitting. The strength of the interaction of carbohydrates with ConA was found to be as follows: maltose>mannose>glucose>lactose>MAN5.

Red/near-infrared/short-wave infrared multi-band persistent luminescence in Pr3+-doped persistent phosphors.

Red/near-infrared/short-wave infrared multi-band persistent phosphors are developed by doping Pr3+ into MgGeO3 and CdSiO3 hosts, which emit intense, very-long-lasting (>120 h) persistent luminescence at around 625 nm, 900 nm and 1085 nm after ultraviolet light excitation. The penetration power of these three wavelengths in chicken breast follows the order of 1085 nm > 900 nm > 625 nm.

Long persistent luminescence in the ultraviolet in Pb(2+)-doped Sr2MgGe2O7 persistent phosphor.

We extend the persistent luminescence into the ultraviolet spectral region by developing a new ultraviolet persistent phosphor Sr2MgGe2O7:Pb(2+). The Sr2MgGe2O7:Pb(2+) phosphor exhibits strong persistent luminescence peaking at 370 nm and a long persistence time of >12 h after excitation. The phosphor also exhibits a photo-stimulated persistent luminescence capability.

Ultra-sensitive in-situ detection of near-infrared persistent luminescent tracer nanoagents in crude oil-water mixtures.

Current fluorescent nanoparticles-based tracer sensing techniques for oilfield applications suffer from insufficient sensitivity, with the tracer detection limit typically at the several hundred ppm level in untreated oil/water mixtures, which is mainly caused by the interference of the background fluorescence from the organic residues in crude oil under constant external excitation. Here we report the use of a persistent luminescence phenomenon, which enables an external excitation-free and thus background fluorescence-free measurement condition, for ultrahigh-sensitivity crude oil sensing. By using LiGa5O8:Cr(3+) near-infrared persistent luminescent nanoparticles as a tracer nanoagent, we achieved a tracer detection limit at the single-digit ppb level (down to 1 ppb concentration of nanoparticles) in high oil fraction (up to 65 wt.%) oil/water mixtures via a convenient, CCD camera-based imaging technique without any pretreatment or phase separation of the fluid samples. This detection limit is about four to five orders of magnitude lower than that obtained using conventional spectral methods. This study introduces a new type of tracer nanoagents and a new detection method for water tracer sensing in oil reservoir characterization and management.

New function of the Yb3+ ion as an efficient emitter of persistent luminescence in the short-wave infrared.

The trivalent ytterbium (Yb3+) ion has been extensively used as an emitter in short-wave infrared (SWIR) lasers, a sensitizer to activate other lanthanide ions for up-conversion luminescence, and a spectral converter in Ln3+-Yb3+ doubly doped quantum cutting phosphors. Here we report a new function of the Yb3+ ion-as an efficient emitting center for SWIR persistent luminescence. We have developed the first real SWIR persistent phosphor, MgGeO3:Yb3+, which exhibits very-long persistent luminescence at around 1000 nm for longer than 100 h. The MgGeO3:Yb3+ phosphor is spectrally transparent to visible/near-infrared light (~400-900 nm) and is a promising ultraviolet-to-SWIR spectral convertor. The MgGeO3:Yb3+ phosphor also exhibits a photostimulated persistent luminescence capability, where the SWIR persistent emission in an ultraviolet-light pre-irradiated sample can be rejuvenated by low-energy light (white or red light) stimulation. The MgGeO3:Yb3+ phosphor is expected to have promising applications in biomedical imaging, night-vision surveillance and photovoltaics.

Facile one-pot synthesis of gold nanoparticles stabilized with bifunctional amino/siloxy ligands.

A method for the direct one-pot synthesis of amine-stabilized gold nanoparticles using 3-(trimethoxysilylpropyl)diethylenetriamine (TMSP dien) is described. The amine groups of this bifunctional molecule act as a stabilizer for gold nanoparticles as they form by reduction of HAuCl4. Highly stable gold nanoparticles with sizes tunable between 8 and 20 nm can be readily obtained. This method is quite simple to implement and environmentally benign as there is no need to add an external reducing reagent. The incorporated siloxy functionality was subsequently used to form a silica shell around the gold particle.